This invention relates to apparatus for open-end friction spinning of the type having two friction rollers that are arranged adjacent one another and form a wedge-shaped gap. The friction rollers are mounted on non-rotating support axles by means of bearings. The support axles are held by means of holding means in the area of the outer end faces of the rollers, the spacing of which holding means can be adjusted.
In the case of known construction described in German Published Unexamined Patent Application (DE-OS) No. 31 41 733, the holding means that are assigned to an axle are, in each case, disposed on a console. One of the two consoles is fastened at the machine frame in a stationary manner, while the other console is guided so that it can be adjusted transversely to the wedge-shaped gap for adjusting the width of the wedge-shaped gap of the rollers. For this purpose, spreading wedges are arranged in the area of both ends between the consoles, said spreading wedges being slidable in the longitudinal direction of the consoles and thus in the longitudinal direction of the axles by means of adjusting screws. The movable console, by means of spring assemblies, is pressed against the spreading wedges. By means of a construction of this type, it is difficult to achieve a sensitive adjustment of the wedge-shaped gap between the rollers which must take place only in the range of several hundredths of a millimeter. In addition, this construction is quite expensive and not suitable for a series-produced machine where about 200 of such spinning devices are provided.
An object of the invention is to develop a device of the initially mentioned type in such a way that the spacing of the rollers can be adjusted sensitively by means of the adjustment of the spacing of the holding means of the axles and wherein the construction is very simple permitting use thereof in a series-produced machine.
This object is achieved according to one aspect of the invention by providing four holding means arranged in pairs for the axles, where at least between the holding means of one pair, an adjusting screw is disposed extending transversely to the wedge-shaped gap by means of which the spacing of said holding means can be adjusted.
By using an adjusting screw extending transversely to the wedge-shaped gap, the adjustment is very sensitive since no other working means have to be provided. In this case, it may be sufficient to adjust the wedge-shaped gap only via the pair of holding means in the area of one end face of the rollers, namely in the area where the spun yarn is formed, i.e., where the starting tip of the yarn is located. The wedge-shaped gap should be the narrowest in this area. For this reason, the adjustability of the wedge-shaped gap in this area, i.e., in the area of the roller end faces facing away from the yarn withdrawal direction, has increased significance in regard to the movability and the setting. Only a few additional elements are required to permit the movability.
In practice, it is advantageous for the holding means to be adjustable against a spring force by means of the adjusting screw. In order not to have to provide any additional components in this case, it is provided in a further development of the invention that the holding means are mounted at a support at a distance to the receptacles for the axles and can be elastically deformed by means of the adjusting screw.
In order to permit a reduction and an enlargement of the wedge-shaped gap in the same manner and to rigidly support the holding means in both directions, it is provided in another development of the invention that an adjusting screw is arranged between the holding means of one pair, said adjusting screw reaching into threaded boreholes of the holding means by means of bolts provided with opposing threads. By means of this development, a very sensitive adjustment can be carried out, where it is not absolutely necessary that one or both holding means are flexible in a spring-elastic manner, as long as one of the two holding means is slidably guided in the adjusting direction.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.